Latching mechanism for a vehicle

ABSTRACT

A vehicle including at least one door releasably securable in a closed position by a power operable latch, the latch being operable by a remotely operable unlatching means to release the door, there being no unlatching means provided on an unsecured part of the vehicle when the vehicle has been secured.

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to Great Britain Patent Application GB 0130422.9 filed on 19 Dec. 2001.

BACKGROUND OF THE INVENTION

[0002] The present invention relates to vehicles, and in particular vehicles including latches operable to releasably secure an associated door in a closed position.

[0003] Known vehicles include latch assemblies mounted on vehicle passenger doors for releasably retaining the door in a closed position. In order to open the door two distinct functions have to be performed. Firstly the latch has to release the striker, and then the door has to be moved from its closed position to its open position.

[0004] Typically a door may include an outside unlatching/opening handle which is utilized to perform these two functions. Thus the handle can be lifted or pivoted relative to the door in order to unlatch the latch and then the same handle is pulled (whilst in its lifted position) so that the door and handle move together to an open position.

[0005] The door may also include an inside door handle, typically mounted on a forward part of the door and pulled by an index finger of a vehicle occupant. Pulling of this handle operates to unlatch the latch and then the occupant can use his elbow to push the door open.

[0006] In order to close the door from the inside, typically a rigid door pull handle is provided which is distinct from the latch operating handle.

[0007] With regard to the outside unlatching/opening handle, it is required to be mechanically connected to the latch in order for it to perform correctly. Furthermore, it has to be ergonomically designed both in shape and position for it to be easily operated by a user. It also has to be designed with aesthetics of the whole vehicle in mind.

SUMMARY OF THE INVENTION

[0008] An object of the present invention is to provide an improved vehicle having fewer components and/or which is easy to manufacture.

[0009] Thus according to the present invention there is provided a vehicle including at least one door releasably securable in a closed position by a power operable latch, the latch being operable by a remotely operable unlatching means to release the door, there being no unlatching means provided on an unsecured part of the vehicle when the vehicle has been secured.

[0010] Advantageously, this provides for a vehicle which does not require any unlatching handles to be provided on the exterior of the vehicle, especially on the door. This simplifies and cheapens manufacturers since no unlatching handles need be provided and consequently no connection of an unlatching handle to the latch need be provided.

[0011] Furthermore, the aesthetic design of the vehicle is no longer restricted by the need for an unlatching handle on the exterior of the vehicle.

[0012] Advantageously this provides for a latch assembly of simplified design.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The invention will now be described, by way of example only, with reference to the accompanying drawings in which:

[0014] FIGS. 1 to 3 show part views of a latch assembly for use in a vehicle according to the present invention, in a latch, unlatched and open condition;

[0015] FIGS. 4 to 8 show part views of a further embodiment of a latch assembly for use in a vehicle according to the present invention when it moves from a latched condition to an unlatched condition.

[0016] FIGS. 9 to 13 show alternative embodiments of vehicles according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0017] With reference to FIGS. 1 to 3 there is shown a latch assembly 10 including a latch bolt in the form of a rotating claw 12, a retention means in the form of a pawl 14, an actuator in the form of an electric motor 16, and a cam 18.

[0018] Rotating claw 12 is pivotable about claw pin 24 from a closed position as shown in FIG. 1 to an open position as shown in FIG. 3. Claw 12 includes a mouth 26, a closed abutment surface 28 and a first safety abutment surface 30.

[0019] Pawl 14 is pivotable about pawl pin 32 and includes a first arm 34 having a first abutment surface 36 and a second arm 38 having a second abutment surface 40.

[0020] Electric motor 16 includes an output shaft 42 upon which is directly mounted cam 18.

[0021] In this case cam surface 20 is circular but since cam 18 is mounted eccentrically relative to output shaft 42, this arrangement provides for a single lobe cam.

[0022] Operation of the latch assembly is as follows.

[0023] Consideration of FIG. 1 shows a striker 22 retained in mouth 26, with claw 12 being retained in its closed position by closed abutment surface 28 co-operating with first abutment 36.

[0024] Under these circumstances the door upon which striker 22 is mounted would be in a fully closed position.

[0025] Note that it is possible for striker 22 to be retained in mouth 26 whilst first safety abutment surface 30 co-operates with first abutment surface 36. Under such circumstances the associated door would be in a first safety position i.e. unable to be opened but nevertheless not in a fully closed position.

[0026] It should be note from FIG. 1 that second abutment surface 40 is in contact with cam surface 20 but cam lobe 21 is remote from second abutment surface 40, thus allowing engagement between closed abutment surface 28 and first abutment surface 36.

[0027] A pulse of current is fed to the motor such that it causes the cam to continuously rotate through 360° and then stop.

[0028] Initial operation of the motor 16 causes the cam 18 to rotate to the position shown in FIG. 2 where cam lobe 21 is proximal second abutment surface 40 thus causing pawl 14 to rotate in a clockwise direction about pawl pin 32 hence disengaging first abutment surface 36 from closed abutment surface 28.

[0029] When the latch is passing through the position as shown in FIG. 2, elastometric door seals acting between the associated door and the adjacent portion of the vehicle causes the door to open such that the striker 22 moves to the right as shown in the figure relative to the latch thereby causing the claw 12 to rotate in a clockwise direction with viewing FIG. 2, such that surface 31 of the claw moves to a position opposite surface 37 of the pawl.

[0030] With continued rotation of the motor and hence cam surface 20, the lobe 21 achieves the position as shown in FIG. 3, i.e. remote from second abutment surface 40 where upon the motor stops. It should be noted from FIG. 3 that cam surface 20 does not engage second abutment surface 40 since these two surfaces are being held apart by cooperation of surfaces 37 of pawl engaging surface 31 of the claw.

[0031] When the door is closed, striker 22 enters mouth 26 causing claw 12 to rotate in a clockwise direction from the position shown in FIG. 3 to the position shown in FIG. 1 whereby surfaces 37 and 31 disengage thus allowing engagement of first abutment 36 with closed abutment surface 28.

[0032] In this case the motor 16 is the sole means of releasing the latch under normal operating conditions. The term normal operating conditions should be construed as meaning those conditions under which an end user of the vehicle would normally open and close the associated door.

[0033] In this case an access path P (shown schematically) is provided in order to open the latch under abnormal operating conditions. Thus when a vehicle is being assembled on a assembly line an independent means such as a screwdriver or other generally elongate element can be passed through the access path in order to operate the pawl 14 to open the latch independent of operation of the motor. Thus advantageously the door can be fitted and aligned and checked for correct opening and closing in the absence of a power source such as the vehicle battery or a slave battery. The term access path should be construed to mean an arrangement of components that allows access of the independent means.

[0034] With reference to FIGS. 4 to 8 there is shown part views of a further embodiment of a latch assembly 10′ including a retention means in the form of a pawl 14′ having a second arm 38′ Pawl 14′ is mounted similar to pawl 14, and engages a rotating claw (not shown).

[0035] Latch assembly 10′ further includes a cam 18′ having a cam surface 20′ with a cam lobe 21′. Cam 18′ is rotatable about axis A which in this case is coincident with an output shaft of an electric motor (not shown).

[0036] In this case a resilient mean in the form of a tension spring 44′ is secured under tension between fixing pin F mounted on a chassis of the latch assembly and connection pin C mounted on the cam 18′.

[0037] Operation of the latch assembly 10 is as follows.

[0038] Consideration of FIG. 4 shows the pawl 14′ in an engaged position, and in particular cam surface 21′ does not contact second abutment surface 40′.

[0039] Operation of the motor causes the cam 18′ to rotate clockwise through 360°. During part of this 360° movement the cam lobe 21′ engages second abutment surface 40′ causing pawl 14′ to rotate clockwise when viewing the figures thus allowing the latch to open (see FIG. 8).

[0040] Consideration of FIG. 4 shows that tension spring 44′ biases the cam 18′ to the position shown in FIG. 4 since this is the position at which the distance between connection pin C and fixing pin F is a minimum. In this position cam 18′ is in a stable equilibrium position i.e. a small rotation of cam 18′ clockwise or anticlockwise will result in the cam returning to the position as shown in FIG. 4.

[0041] Consideration of FIG. 5 shows the cam having been rotated through 90° whereupon tension spring 44′ has been extended.

[0042] Consideration of FIG. 6 show the tension spring being further extended with the cam having being rotated through 180°. In this case axis A is on a line joining connection pin C to fixing pin F. Whilst this position is being moves through transiently, nevertheless the cam 18′ is momentarily in an unstable equilibrium position. Thus should the motor fail in this position, the cam would remain in this position but should the cam be slightly displaced clockwise the spring would move the cam clockwise to the position as shown in FIG. 4 and should the cam be displaced slightly anticlockwise the spring would move the cam to anticlockwise to the position as shown in FIG. 4.

[0043] Consideration of FIG. 7 shows that the cam has moved beyond the unstable equilibrium position of FIG. 6.

[0044] It should be noted that during all the movement of the cam from FIG. 4 to the position shown in FIG. 7, the cam surface 20′ does not engage the second abutment surface 40′ of the pawl 14′.

[0045] Thus it is only during the latter part of the rotation of the cam that the cam lobe 21′ engages second abutment surface 40′ to move the pawl 14′ to a disengaged position (as shown in FIG. 8).

[0046] In particular the tension spring 44′ can be designed such that the amount of power required to move cam from the position shown in FIG. 4 to the position shown in FIG. 6 is greater than the amount of power required to open the latch. Thus under these circumstances if the motor was to fail such that it lost power, then subsequent operation of the motor to open the door would result in the motor being unable to move the cam from the position shown in FIG. 4 to the position shown in FIG. 6. Under these circumstances the door would remain closed which is preferred to a door that cannot be retained in a closed position.

[0047] Furthermore the tension spring 44′ can also be designed such that if the motor losses all power when the cam is in the position as shown in FIG. 7, the tension spring has sufficient energy stored therein to move the cam from the position as shown in FIG. 7 to the position as shown in FIG. 4. Again this results in a door that can be held in a closed position.

[0048] In further embodiments alternative latch bolts could be used, in particular non rotating latch bolts. Furthermore alternative retention means could be used. Furthermore alternative actuators such as pneumatic or hydraulic actuators could be used. Furthermore the cam need not be mounted directly on the actuator output shaft, for example a gear system could be used between the output shaft of the actuator and the cam.

[0049] With reference to FIGS. 9 and 10 there is shown schematic views of vehicles V1 and V2 including doors FRD, FLD, RRD, and RLD having unsecured parts 50 a, 50 b, 50 c and 50 d, respectively.

[0050] For ease of reference the following references will be used, where appropriate on FIGS. 9 and 10.

[0051] M=Motion Switch

[0052] I=Inside Release Switch

[0053] R=Remote Release Switch

[0054] CS=Child Safety Switch

[0055] FRL=Front Right Latch

[0056] FLL=Front Left Latch

[0057] RRL=Rear Right Latch

[0058] RLL=Rear Left Latch

[0059] EPS=Emergency Power Socket

[0060] C=Circuit

[0061] FRD=Front Right Door

[0062] FLD=Front Left Door

[0063] RRD=Rear Right Door

[0064] RLD Rear Left Door

[0065] SL=Superlock Switch

[0066] Z=Remote Release Device

[0067] The switches fall into two classes. Thus the remote release switch and the inside release switch are all biased to an open position with a positive action being required to close the switches.

[0068] The motion switch, child safety switch and superlocking switch are all bi-stable switches, that is to say they have a stable open position and a stable closed position.

[0069] Consideration of FIG. 9 shows that vehicle V1 (shown schematically) includes four passenger doors (shown schematically) FRD, FLD, RRD and RLD. Each door includes an associated latch FRL, FLL, RRL and RLL which releasably secures the appropriate door in its closed position. These latches can be either of the embodiments shown in FIGS. 1-3 or 4-8 or alternatively can be different embodiments. The latch engages a striker (such as striker 22) which is secured to a fixed structure of the vehicle. Operation of the latch will cause the latch bolt (typically a rotating claw such as claw 12) to release the striker where upon the door will move to an ajar position by virtue of a door seal, mounted at the periphery of the door acting to move the door to the ajar position. From the ajar position the user of the vehicle can then manually move the door to its fully open position.

[0070] All latches on FIG. 9 are identical part from the position at which they are mounted on the vehicle.

[0071] Thus the latch FRL is a power operable latch, which when powered releases the striker from the latch claw thus allowing subsequent opening of the door.

[0072] Power can only be fed to latch FRL when the motion switch M is in a closed position. This occurs when the vehicle is either stationary or is moving below a predetermined speed (such as 5 km per hour).

[0073] Once the vehicle has exceeded the predetermined speed, then the motion switch opens and it is not possible to open any of the doors. Once the vehicle has slowed to below the predetermined speed or has stopped, the motion switch closes automatically.

[0074] With a vehicle stationary, and with an occupant requiring to exit door FRD, a vehicle occupant can manually press the inside release switch associated with that door. This will allow power to operate the latch and hence release the door.

[0075] It should be noted that all of the inside release switches I are located on the inside of the vehicle and are thus not accessible to unauthorized persons (such as car thieves) when the vehicle has been secured (i.e. when all of the door have been closed and all other apertures such as windows and sun roofs have also been closed or substantially closed).

[0076] Remote release switch R can only be operated by the remote release device Z.

[0077] The remote release device typically is a small hand held device which the vehicle driver would carry about him when remote from the vehicle.

[0078] It can be an active device i.e. requiring an active input from the vehicle owner in order to arrange for remote release switch to close, or alternatively it can be a passive device such that when a person carrying the device is within a certain range of the vehicle then one or more remote release switches R are caused to close.

[0079] Note that an embodiment shown in FIG. 9 the remote release switches have been shown positioned on their appropriate doors. However, in further embodiments the remote release switches need not be positioned on their appropriate doors and typically might be positioned inside the control unit (with appropriate circuitry) to ensure the switch is topologically in the same position in the circuit C.

[0080] Furthermore, a child safety switch (CS) is provided (shown in an open position) to provide for a child safety feature on the rear doors thus with the child safety switch shown in the position as shown in FIG. 9 the rear doors will not open when their appropriate inside release switches are manually operated. Child safety switch can be open or closed at the drivers option depending upon the age of any rear seat occupants of the vehicle.

[0081] In particular it should be noted that there is no outside release switch on the vehicle i.e. no switch mounted on the outside of the vehicle which can be operated to open any latch. However, the vehicle may include a fixed door pull handle, the sole function of which is to swing the door from an ajar position to an open position. In particular it should be emphasized that such a handle does not operate to unlatch the latch. Because of this, the vehicle automatically goes into a locked state when the doors are shut since there is no means of opening the doors mounted on the outside of the vehicle. This can be contrasted known vehicles which have externally mounted latch release handles. On such known vehicles even with all the doors shut, the vehicle may not be locked, since in order to lock the vehicle the externally mounted latch release handles must additionally be disabled. It can be seen that no such additional disablement is required on the present invention simply because no such external mounted latch release handles are provided. None of the unsecured parts 50 a, 50 b, 50 c and 50 d of the vehicle have a latch.

[0082] The remote release device Z can take many forms.

[0083] In this case it is an active system having four push buttons Z1, Z2, Z3 and Z4. Each push button is associated with an appropriate door. Thus pressing one of the buttons on the remote release device will release one door. In order to open all four doors using just the remote release device then all four buttons have to be pushed.

[0084] Alternatively a single button on a remote release device can be associated with a set of doors and a further push button being associated with a different set of doors. Thus on a remote release device having two buttons pressing of the first button could open, say, the front doors and pressing of the second button could open, say, the rear doors.

[0085] Alternatively pushing of the first button could open, say, the drivers door and pushing of the second button could open, say, the front passenger door and the rear doors.

[0086] Alternatively pushing of the front button could open say the drivers door and pushing of the second button could open say all doors (including drivers door).

[0087] Alternatively the remote release device could have just one button which when operated in a specific fashion could open different sets of doors. Thus pressing the button once could open the drivers door and pressing the button twice in quick succession could open all doors.

[0088] Consideration of FIG. 10 shows a vehicle V2 identical to vehicle V1 accept that vehicle V2 includes a superlock switch SL. It can be seen that this switch is in series with all inside release switches I as such when it is in the open position as shown in FIG. 10, operation of the inside release switches I by say a thief who has gained access to them by breaking a window, will not unlatch the latch, and the doors will remain closed.

[0089] Additionally it should be noted that in this case the remote release switches R and the inside release switches I are no longer mounted on their appropriate doors. The inside release switches I can be mounted at any convenient location which is readily accessible to a person sitting in the vehicle adjacent to the appropriate door. Thus the switches can be mounted on fixed bodywork of the vehicle, or a central console.

[0090] Furthermore, the vehicle includes an emergency power socket EPS to which an external power source such as a battery can be connected when the vehicle battery has gone flat.

[0091] The preceding description is exemplary rather than limiting in nature. Variations and modifications to the disclosed examples may become apparent to those skilled in the art that do not necessarily depart from the essence of this invention. The scope of legal protection given to this invention can only be determined by studying the following claims. 

What is claimed is:
 1. A vehicle comprising: at least one door releasably securable in a closed position by a power operable latch, the latch being operable by a remote device to release the door and no unlatching mechanism is provided on an unsecured part of the vehicle when the vehicle is secured.
 2. The vehicle as defined in claim 1 further including a further unlatching mechanism provided on a secured part of the vehicle when the vehicle has been secured.
 3. The vehicle as defined in claim 2 wherein a disabling mechanism is provided to prevent the further unlatching mechanism from operating the latch to release the door.
 4. The vehicle as defined in claim 3 wherein the disabling mechanism prevents the further unlatching mechanism from operating the latch when the vehicle is moving above a predetermined speed.
 5. The vehicle as defined in claim 3 wherein the disabling mechanism operates to prevent the further unlatching mechanism from operating the door when the vehicle is stationary.
 6. The vehicle as defined in claim 3 further including a plurality of doors, each door having an associated further unlatching mechanism, in which the disabling mechanism acts to prevent some but not all of the further unlatching mechanism from unlatching their associated doors.
 7. The vehicle as defined in claim 1 further including a plurality of doors in which the remote is operated to independently release a first set of doors and a second set of doors, the first set of doors being different from the second set of doors.
 8. The vehicle as defined in claim 7 in which the first set of doors is a single door and the second set of doors is a single different door.
 9. The vehicle as defined in claim 7 in which the first set of doors is a drivers door and a second set of doors is all doors of the vehicle.
 10. The vehicle as defined in claim 7 wherein the first set of doors is two front doors and a second set of doors is all the doors.
 11. The vehicle as defined in claim 1 wherein the doors are passenger doors.
 12. The vehicle as defined in claim 1 wherein the power operable latch is a latch assembly including a latch bolt, a retaining mechanism and an actuator, the latch bolt being moveable between a closed position at which the latch bolt is capable of retaining a striker and an open position at which the striker is released, the retaining mechanism being moveable between a retained position at which the retaining mechanism retains the latch bolt in at least the closed position and a released position at which the latch bolt can move between the opened position and closed position, the actuator being capable of moving the retaining mechanism from the engaged position to the released position, in which, under normal operating conditions of the latch, the actuator is the only way of releasing the latch.
 13. The vehicle as defined in claim 1 wherein the latch is a latch assembly including a latch bolt, a retaining mechanism, an actuator and a cam having a cam surface, the latch bolt being moveable between a closed position at which the latch bolt is capable of retaining a striker and an open position at which the striker is released, the retaining mechanism being moveable between a retained position at which the retaining mechanism retains the latch bolt in at least its closed position and a released position at which the latch bolt can move between the closed and the open position, the retaining mechanism further including an actuation abutment, the actuator being operable to move the cam, the cam surface engaging the actuation abutment of the retaining mechanism to move the retaining mechanism to the released position.
 14. The vehicle as defined in claim 1 wherein the latch is a latch assembly including a latch bolt, a retaining mechanism and an actuator, the latch bolt being moveable between a closed position at which the latch bolt is capable of retaining a striker and an open position at which the striker is released, the retaining mechanism being moveable between a retained position at which the retaining mechanism retains the latch bolt in at least the closed position and a released position at which the latch can move between the open and closed position, the actuator being capable of moving the retaining mechanism from the engaged position to the released position, in which the actuator is biased towards an at rest position, wherein the retaining mechanism is capable of achieving one retained position, by a resilient member.
 15. The vehicle as defined in claim 1 further including a plurality of power operable latches, at least two of said plurality of power operable latches being identical. 